Kettle drum and timpani therefor



W. F. LUDWIG KETTLE DRUM AND TIMPANI THEREFOR April 4, 1950 4Sheets-Sheet l Filed Aug. 30, 1946 April 4, 195o w. F. LUDWIG 2,502,733

KETTLE DRUM AND TIMPANI THEREFOR FiledAug. so, 194e 4 sheets-sheet 2 INVEN TOR.

a' @We Flu@ April 4, 1950 w. F. LUDWIG 2,502,733

KETTLE DRUM AND TIMPANI THEREFOR Filed Aug. 30, 1946 4 Sheets-Sheet 3April 4, 1950 w. F. LUDWIG 2,502,733

y KETTLE DRUM AND TIMPANI THEREFOR Filed Aug. 50, 1946 4 Sheets-Sheet 4@4Z/@Ma fffey Patented pr. 4, 1950 UNITED sTATEs PATENT OFFICE KETTLEDRUM AND TIMIAN THEREFOK William F. Ludwig, Chicago, lll.

Application August 30, 1946, Serial No. 694,901

'being crated and shipped to purchasers at far less cost and is moreeasily capable of being transported from one location to another by theIowner in an automobile or other passenger vehicle without being crated.

A further object of the invention is to provide a structure wherein thetympani is disposed entirely within the drum shell and the latter andthe operating lever thereof, together with supporting legs, are mountedupon a plate removably secured to the bottom of the drum shell, the legs'being capable ofl adjustment to project almost entirely into the drumshell preparatory to transport thereof to another location. 1

A further object of the invention is to provide an improved tympani forthe drum.

In the accompanying drawings illustrating suitable embodiments of theinvention:

Fig. l is a diametric sectional view of a drum constructed in accordancewith the invention.

Fig. 2 is a plan sectional view of the same taken on the line 2-2 ofFig. 1. Fig. 3 is a fragmentary detail radial sectional View, on anenlarged scale, showing one of the conventional drum head tensionadjusting devices of the drum.

Fig. 4 is a fragmentary detail vertical sectional view, on an enlargedscale, taken on the line 4 4 of Fig. 1.

Fig. 5 is a fragmentary detail vertical sectional view, on an enlargedscale, taken on the line 55 of Fig. l.

Fig. 6 is a detail plan view of the head with which the links, connectedwith the structure of Fig. 3, are connected at their inner ends.

Fig. 7 is a perspective view of the tympani plate connected with thehead shown in Fig. 6.

Fig. 8 is a perspective view of a wedge member of the tympani.

Fig. 9 is a fragmentary detail sectional view, on an enlarged scale,taken on the line 6-6 of Fig. 1, showing means for adjusting a memberconnected with the foot lever of the structure.

Fig. 10 is a top plan view, on an enlarged scale, of the tympanisupporting plate of the structure.

Fig. l1 is a vertical sectional View, on an enlarged scale, taken on theline II-II of Fig. 10, 'showing a modied form of tympani mechanism inside elevation. f

Fig. 12 is a vertical sectional view taken on the Fig. ,13 is a verticalsectional view taken on the line I3-I3 of Fig. 12.

Fig. 14 is a side elevation of the structures shown in Figs. 12, 13 and15, the yoke ofthe structure being partly broken away.

Fig. 15 is a view of the yoke of the structure of Figs. l, 13 and 14,shown partly in section.

Fig. 16 is a fragmentary detail vertical longitudinal section view of aportion of the foot lever shown in Fig. 11.

The drum, as shown in Fig. 1, includes the kettle or shell I, which isusually semi-spherical, but in the instance illustrated is ofsubstantially the shape of the smaller end portion of an egg and,therefore, of greater depth proportionately to the diameter of its rimthan is true of the conventional drum kettle.

The said kettle or shell I is equipped with the conventional hoop 2 towhich the marginal por tion of the drum head 3 is secured, the latterbeing equipped with conventional projections 4 (Fig. 3) equipped withopenings constituting bearings for the shanks of the screws 5. Threadedend portions of the said Shanks are engaged in a conventional mannerwith the elbow portions of bell crank levers 6 secured pivotally at oneend to the shell I and connected at their other ends with the outer endsof links 1 which project through openings in said shell I and areconnected at their inner ends with the head 8 (Figs. 6 and '7) oi thetympani of the drum, as described hereinafter. i

The above described structures of Fig. 3 are usually six or eight innumber and are equally spaced apart.

The said shell I is equipped at bottom with a central opening, and atthree equally spaced apart points, which are also spaced equi-distantlyfrom the axis of said shell I, with openings 9 through which thesupporting legs IU of the structure project, said openings 9 beingdisposed in staggered relation to the said links 1.

inwardly of the openings 9, the shell I is equipped, in the instanceillustrated, with a series of six equally spaced apart openings II, alsospaced equi-distantly from the axis of the shell, and three which arealigned radially with the openings 9, for the passage of bolts whichsecure the dished plate I2 to said shell I, said plate being shown intop plan view in Fig. 13.

Said plate I2-is equipped at three equally spaced apart marginal pointswith contractible conventional sleeve iormations I3 through which the 3tubular supporting legs IU pass and wherein they are clamped againstmovement by operation of the sleeve contracting screws I4.

Said plate I 2 is equipped on its lower face with a pair of parallelprojections I5, aligned radially With the axis of one of the said sleeveformations I3, between which one end of the foot lever It is securedpivotally.

The said foot lever I6 is channeled to receive one arm of the bell cranklever Il which also is pivotally connected with said projections I5. Theother arm of said lever projects into the said shell I of the drum andis rendered adjustable relative to the lever I6 by means of a set screwIlq, which engages in a threaded opening in the lower arm of the bellcrank lever Il and has one end portion projecting freely through anopening in the web of said lever I 6, said end portionv of said setscrew being equipped with annular grooves in which split wire collarsI'Ib are engaged to hold said .screw against longitudinal movement.

Secured pivotally at one end to the said inner arm of said lever Il is apair Aof parallel wedge members I8, of the preferred form of tympani of.the drum, one wedge member I8 being shown in The said tympani includesa pair of parallel flat vvertical plates I9 (Fig. 5) which may beintegral with or suitably secured rigidly to the plate I2. Disposedmidway between said plates I9 is a flat vplunger 28 (Fig. 8) equipped inits lower end portion with an opening 2 I constituting a bearing ior ashaft 22, which carries a pair of shoes 23, 'disposed upon oppositesides ofsaidplunger 20.

The outer end portions of said shaft 22 pass through vertical slots 24,of width equal to the diameter of said shaft, in the said plates I9.

A similar shaft 25 which carries a similar pair ofshoes 28, bearing uponthe upper surfaces of said wedge members I8, is journalled at its endsin lthe side plates I9. v The said shaft 25 passes through thelongitudinal slot 2'I of the said plunger 20.- i f i I r Said plunger 20is equipped at its upper end Zwith a boss 28 equipped with a threadedopening to receive the lower end portion of a threaded link i2!!rotatably associated with the said head 8 `against longitudinal movementrelative to the latter.

Thus when the foot lever I6 is depressed, the wedge members I8 are movedinwardly relative to the shoes 23 and 26 and thus the plunger 20 andhead 8 are moved downwardly and thereby cause the links l to turn thebell crank levers 6 and. draw the hoop 2 downwardly to tension the drumhead 3 to a degree determined by the extent to which the foot lever isdepressed.

It will be noted that the long arm of the foot lever I6 is curved sothat when swung upwardly to the dotted line position of Fig. l, it willbe disposed closely adjacent to the shell I, this being its positionwhen the structure is crated for shipment. The legs I are thenpositioned relative to the bottom wall of the crate so that the lowestpoint of the lowest projection of the plate I2 .will be spaced from saidbottom wall of the crate.

The above described tympani structure is very simple, but because ofhigh tension stress that must be overcome thereby, and the4 requirementthat when the drum head 3 is under any degree,

and particularly under its maximum degree of tension, and the operatorsfoot is withdrawn from the foot lever I6, the said lever must remain inthe position to which it has been moved, the angle of divergence of theupper and lower surfaces of the Wedge members I8 from each other, maynot be more than seven degrees, the swing of said lever I6 and thecorresponding length of stroke of the wedge members I8 is required to berelatively long to cover a full octave range of tone of the drum.

The said wedge surfaces and those of the shoes 23 and 26 opposed theretoare required to be very accurately plane and smooth and maintainedlubricated sufiiciently to avoid squeak or chattering `during operationsof said foot lever I6.

Obviously the muscles of the operators leg used may not' be maintainedtense due to the requirement that the position of the lever I6 must bemaintained at any given position against any movement up or down fromsaid position while the tone of the drum required needs to be maintainedduring any time period short or long without fatiguing said muscles.

Therefore, when said lever I6 has been depressed or raised to any level,the operators muscles should be capable of being relaxed while the footrests upon said lever. The resistance to movements of the latter must besuch as to render the same capable of bearing the weight thus imposedupon it without eiecting further depression of said lever and, also,preferably, without requiring any muscular action to retain said leverin that position. To raise the lever from any level to a higher oneshould also require a slight muscular effort of the operator.

Because of these requirements, or, at least highly desirable results tobe attained, the frictional resistance to self-restoration of the drumhead 3 to low tension and the sustaining of the weight imposed upon thelever I6 when muscles are relaxed as aforesaid, and it being obviousthat said weight varies proportionately to the weight of the operator,the accuracy of shape and the areas of the opposed surfaces of the saidwedge members and shoes is required to be of a relatively high precisiontype.

If the angle of divergence of the said wedge sur faces is reduced, thelength of stroke of the wedge members must be increased proportionatelythereto to effect the same length of stroke of the plunger 20 of thestructure and a correspondingly longer arc of swing of the foot leverI6, a longer stroke being undesirable.

Adjustment of the bell crank lever II relative to the foot lever I6operates to correct all possibility of having the lever I 6 bear uponthe floor before maximum tension of the drum head 2 has been attained.

The upper and lower surfaces of the wedge lmembers I8 is limited,preferably, to an angle of no more than seven degrees to overcome theirreverse movement responsively to the tension stress imposed upon thelower shoes 23 and consequent requirement that the operator maintainpressure upon the foot lever I6 to maintain said head 2 tuned to thedesired note or tone, it being obvious that this pressure requirementincreases progressively as the foot lever is lowered.

The above described structure meets all of the said requirements asnearly perfectly as highly skilled workmanship permits.

The structure illustrated in and by Figs. 10, 11 and 12 constitutes asubstitute for the tympani structure described hereinabove.

As show-n Fig. 11, said structure comprises the cam member 30 rigid withthe shaft or trunnions 3l. As shown in Figs. 12 and 13, said shaft ortrunnions 3| 'engage in short vertical slots 32 in the side plates 33yof 'a casing Awhich `includes end plates 34 `secured to the plate 12.

The said cam member 30 comprises a lower arcuately surface portion 35which is eccentric to its axis of rotation, the center of said eccentricsurface 35 being at the point 36 and aligned hori zontally with the axisof the cam member 30. Said surface 35 is semi-circular.

Above the normally horizontal plane of the axis of said member 30 andits surface 35, is another arcuate surfaced cam portion, the arcuatesurface 31 of which has its axis disposed in said horizontal plane at apoint 38 between the axis of the cam surface 35 and the axis of themember 30, the spacing of said point 38 from the axis of the member 30being subject to variation to increase or decrease the degree ofeccentricity of the surface 31 to the axis of the member 3D.

A shoe 39 of shape similar to a brake shoe of a railway car wheel andhaving an arcuate surface of radius equal to that of the surface 35, andopposed to the latter, is equipped with a shaft or trunnions 40, whichproject through the vertical slots 4I in the side plates 33 of thecasing, the axis of said shaft or trunnions 4U lying in the verticalplane of the axis of the member 30.

Another shoe 42, similar to the shoe 39, the shaft or trunnions 43 ofwhich are'journalled in said side plates 33 in vertical alignment withthe trunnions 40 and the axis of the member 30, is opposed to thearcuate surface 31 of the member 30.

A yoke 44 equipped with bearings 45 for the trunnions 40, and whichproject through the slots 4| of said side plates 33, connects thetrunnions 40 with the tension link 29 and thus with the head 8 to whichthe tensioning links 1 are secured.

As the centers of the arcuate surfaces 35 and 31 are both disposed tothe left of the axis of the member 30, it follows, obviously, that thestress exerted by the shoe 39 upon the arcuate surface 35 causes theshoe 39 to be moved downwardly and the cam member 30 to be forcedupwardly so that the cam surface 31 bears with equal pressure upon theopposed surfaces of the shoes 39 and 42, and thus both said shoes 39 and42 tend to turn member 30 in respectively opposite directionsresponsively to the tension stress applied to the shoe 39, but withrespectively different degrees of force proportionately to thedifference in degree of eccentricity of the surfaces 34 and 31,respectively, to the axis lof the cam member 30.

The latter is equipped with the projection 46 which is connected bymeans of the link 41 with the foot lever I6, the last-named connectionbeing rendered adjustable along said lever in any suitable manner asexemplified in Fig. 15.

As the lever i6 is depressed, the cam member 30 will be rotatedanti-clockwise through a length of arc determined by the distancebetween the pivotal axis of said lever I6 and the axis of its pivotalconnection with the said link 41.

The shoe 39 is thus forced downwardly a distance far greater than thecam member 30 is forced upwardly, both shoes 39 and 42 being turnedslightly on their pivota1 axes in respectively opposite directionsduring this movement of said cam member 30, but not equally so. Duringthis movement, the axis of the cam member 30 will approach 'that of theyshoe 142slightly while the axis of fshoe 139 will become spacedprogressively .farther from the camwax'is.

For example, if the arc of vrotationof 'the .lever I6 is fixed at thirtyydegrees to cover the #entire tone range of the ydrum covering oneoctave, and this requires the shoe 39 to be moved downwardly a distanceof ythree-sixteenths of an inch during said swing of the lever I6, thenthe eccentricity of the cam surface 35 to the cam axis may be of .suchdegree as to cause the shoe 39 to move downwardly one-quarter inch whilethe .cam -30 moves upwardly only one-sixteenth of an inch as determinedby the degree of eccentricity of the respective cam surfaces 35 and 31to the cam axis.

The shoe 42 acts more particularly as a brake shoe, the efficiency ofwhich is increased by reason of the pressure exerted thereby upon thecam 30 counter to the pressure exerted thereupon.

by the shoe 39.

In both the tympani structures shown and described, the upper shoesoperate as brake members, but in the last described structure thearcuate surfaces of the shoes are of greater length with respect to thelength of the shoes than is true of the shoes of the first describedstruc ture.

The cam member 30 and shoes 39 and 42 may be composed of laminated sheetmetal plates wherein steel and bronze plates are alternated in suchmanner that each bronze plate of the cam member 30 is opposed to steelplates of the shoes 39 and 42.

Obviously, in both the tympani structures, the upper and lower shoes areforced apart by wedge action.

As shown in Fig. 14, the lower end of the link 41 may be connectedpivotally with the foot lever I6 at any one of a plurality of spacedapart points consisting of a series of arcuate recesses 48 in the upperwalls of longitudinal slots 49 in the flanges of said lever I6.

I claim as my invention:

In a conventional kettle drum, a dished plate shaped to fit the centralbottom portion of said drum and removably secured thereto and equippedmarginally with contractible clamping sleeves aligned axially withopenings in the drum shell, drum supporting legs projectingtelescopically through said sleeves, a tympani comprising an invertedV-shaped frame rigidly mounted upon the upper concave face of said plateand projecting into the drum shell, a brake shoe mounted pivotally uponthe side plates of said frame in the upper portion of the latter andequipped with a lower arcuate face, a vertically reciprocable membermounted for vertical movement in the lower end portion of said frame andconnected at its upper end with the links connected with the drum headtensioning hoop, vertical guide formations in the arms of said frame, alower shoe mounted pivotally in said reciprocable member in alignmentWith said upper shoe and having an upper arcuate face, a rocking cammember interposed between said shoes and equipped with arcuate facescorresponding in radius respectively with the faces of said shoes, thelower shoe engaging face of said cam member being eccentric to itspivotal axis to effect movement of said reciprocable member whenrotated, said cam member equipped with a peripheral projection betweensaid respective arcuate faces thereof, a foot lever pivotally connectedat one end with the bottom portion of said plate at a point speed fromthe centef thereof and arranged to swing in a diametric plane of thedrum axis,and a link connecting said cam member projection and saidlever at a point spaced from the plate center at the opposite side ofthe said center from which the pivot of said foot lever is spaced.

- WILLIAM F. LUDWIG.

REFERENCES CITED Numloei` v Re. 16,226 1,561,790 2,150,981

UNITED STATES PATENTS' Name Dafne Strupe Dec. 15, 1925 Ludwig et al Nov.17, 1925 Ludwig Mar. 21, 1939 Ludwig et a1 Nov. 4, 1941

